1. Field of the Invention
This invention is for use in the field of dental health where dentists or dental hygienists treat patients by cleaning and polishing teeth and/or by massaging gums.
2. Description of the Prior Art
The mechanical prophylactic angle hand pieces of the knob type are used extensively. The knob of the hand piece is smooth and the rubber cup inserted over the knob slips or stops under pressure. In other cases the rubber cup or dental applicator falls out of the hand piece.
This invention is an improvement on a hand piece of the type disclosed in the Graham U.S. Pat. No. 3,727,313 of Apr. 17, 1973 and in the patents cited therein. Other prior art patents lcoated during a novelty search include the Burlow U.S. Pat. No. 1,314,125 of Aug. 26, 1919; Stempel U.S. Pat. No. 1,417,584 of May 30, 1922; Blair U.S. Pat. No. 2,135,933 of Nov. 8, 1938; and the Kean et al U.S. Pat. No. 3,142,138 of July 28, 1964.
In the past the rubber cups have in certain cases been positively secured to the driven members by screws. This requires time to complete and is an inconvenience to the dentist.